There is known a game machine installed at a game center or the like, where a card is placed on a stage surface. The game proceeds according to the attributes of such card (JPA-2005-46649).
According to JPA-2005-46649, the stage surface is configured to transmit invisible light. An imaging unit such as an image sensor disposed under the stage reads a code of a particular shape printed on the back surface of the card with invisible ink, thereby causing the game to proceed.